Senerio: Contractor does a 100 amp to 200 amp service upgrade to a single family home. The meter, and 100 amp panel, were located in the basement. The new meter is now located outside of the garage,and a new 200 amp panel is located on the inside wall of the garage. The old panel was left in the basement as a subpanel. The contractor fed the old panel with pvc from the new 200 amp panel. In the pvc are the two ungrounged legs, the neutral,and the main grounding electrode/equipment grounding conductor(one wire which hits a lug on the ground bar{neutral is isolated} then proceeds through the panel to the water meter located a couple feet away).Here's my question. Can the main g.e.c also be used as a e.g.c? I know system grounding is different then equipment grounding, but besides by definition is there an applicible article in the code I can refer to?
